In WO 00/26483 a method and a profile for connecting building blocks is described resulting in a wall in a building system. According to this method, two construction blocks are joined along an edge face of each block abutting each other by a profile having a web and two flanges on each side with a perpendicularly extending flap at the distal ends of these two flanges. These flaps are inserted into a groove in the construction blocks whereby the blocks are held together.
This method is advantageous since prefabricated construction blocks may be provided off site and transported to the building site together with other materials and may be assembled on the building site. However, if the rectangular frame is subjected to a twisting force, the gripping flanges may slide out of the slits in the insulation making the entire building system unstable.
In WO 2004/076764 a joining device for joining building boards is described wherein a sandwich-construction is provided by covering panels and an insulation layer enclosed thereby. According to the device a wood material body, bonded to at least one of the covering panels, can be inserted between the building boards. Further, the disclosed joining device may be used in connecting two building boards in a right angle using U-shaped bars, having a base element and two legs abutting the covering panels of the building boards.
This method is advantageous since connecting two building boards in a right angle using U-shaped bars may form a construction wherein weight is supported by both the U-shaped bars and the covering panels. However, in some situations it is not desirable to have weight supported by both the U-shaped bars and the covering panels and in addition, the joining device disclosed in WO 2004/076764 is not well protected against thermal and acoustic bridging.